Radiant swathes of sunlight slice through the skylights and factory windows, illuminating the cement floors. A symphony of sound wafting from machinery builds and arcs in the air around us, and trays of pottery gently rattle as they are wheeled across the floor. We’re here at the Heath Ceramics factory in Sausalito, California, ten minutes north of San Francisco via the Golden Gate Bridge. Constructed in the late 1950s by the architecture firm Marquis & Stoller, the building’s open floor plan is resplendent with all the hallmarks of mid-century architecture: troughed beam ceilings, a central courtyard, and plenty of natural light. But while chic greenery and minimalist outdoor furniture are a feast for the eyes, it’s the pottery that takes center stage at this legendary landmark.

Founded by Sausalito residents Edith Heath and her husband Brian in 1948, Heath Ceramics is perhaps best known for its lines of dinnerware and tile. A self-taught ceramicist, Edith’s work was nationally renowned, especially her glazing experiments, and Brian oversaw engineering and equipment, as well as managing the business. Many of Edith’s earliest produced pieces of pottery (like the Coupe dinnerware collection and the famous Studio Mug) remain in production, and Brian’s uniquely-designed pieces of equipment are still in use today.

A sense of ownership and experimentation is alive and well at the company. Beginning in 2015, Heath clawed back their wholesale portion of the business and is now fully focused on making and selling everything themselves, preferring to do things their way. The factory here in Sausalito used to produce both tile and dinnerware but now focuses just on the latter, with the newer Heath building San Francisco’s Mission District owning tile production.

Heath obtains their white clay from a company in Sacramento. The clay arrives in powder form, and at 600 pounds per bag, mixing it with gray water in the enormous blender is no easy feat. After this mixing comes a filter press, where excess water is squeezed from the clay.

Once the clay comes out of the presses, it goes into the pug mill, which forms the clay into pugs, thick cylindrical shapes that are about the size of a foam roller. The pugs will later be cut down to the appropriate size for molds for everything in Heath’s various dinnerware lines.

The ghostly white plaster molds in varying sizes line the cabinets and high shelves along the wall like a portrait gallery. Molds for plates, mug handles, and platters tell the story of the company through the years. All clay that gets trimmed away from these dinnerware molds is eventually reused. According to Lee Jakobs, Heath’s Creative Communications Director, the company is at a point where they produce almost zero actual waste. One way this is achieved by mixing old clay with new clay and gray water, squeezing out of the pug mill and being reborn as useable clay once again, among other ways to make production lean and nearly zero-waste.

Heath’s trimming stations consist of an entirely female workforce. After the objects have sat in open air for about two and a half hours, they are in that special limbo between damp and dry, structurally sound but still malleable and ready to be trimmed and cleaned up. Every step in this process is done by hand, and tiny flecks of curved clay grow more and more numerous at the trimming stations, resembling piles of gray shredded cheese.

We’re nearing the end of the factory tour, as evidenced by the sight of the curved metal glazing booths. These station staples are made from carved out oil drums, ingenuity from the very beginning when Brian and Edith first built the place.

In the glazing area, a handful of glazers stand in specially designed blue aprons made of a material that sloughs off dust and clay particles. Like every workstation at Heath, glazing is a delicate mix of art and science. Heath makes all of their glazes in-house, and the amount of time it takes to become a fully-trained Heath glazer takes around six months. All of the liquid sprays are measured by weight, down to the very last gram. Anything that’s a 3-D vessel, like a coffee cup, is dipped in the glaze rather than sprayed on. This is because applying a consistent glaze via a spray gun to the inside of a cup will not yield the desired level of consistency. Rim lines are left exposed, wiped bare and clean with a damp sponge.

The last glazing station on the factory floor, right before you reach the massive kilns, is where Winnie Crittenden hangs her apron. Winnie’s title at Heath Ceramics is Glaze Development Technician, but her history with the company goes back 42 years. Winnie is Edith Heath’s niece, and she first started spending quality time at the Sausalito factory when she was just out of college, back in 1971.

Samples and artifacts surround Winnie’s workspace, and Winnie recalls her early days at Heath, observing Aunt Edith. “She was constantly doing experimentation,” Winnie says. “She did experiments on tiles that were seconds. We’d get out the glazes and do a thing called a rosette, where you turn the pressure down on the gun, and other various treatments, to repurpose the tile. They’d come out even more beautiful. So then we did it on dinnerware. We did a landscape, which is pouring glazes across the plates, in a landscape motion.” She gestures with her hand as if washing a car windshield.

“We’d lay down every glaze on top, like a grid. Edith looked for the places where they crossed and that’s where we would go. Generally, Edith liked to put a matte glaze over a shiny one because generally, you’d get more interaction, but I discovered that you don’t want to get stuck in that.”

Sometimes, tests come out a little bumpy – quite literally. “I was trying to show the interaction of the two glazes without it being so heavy. So I’d put the top glaze on, then rub it off, put the first layer on with a sponge, then we’d spray layer after layer, sometimes five or six layers on top of each other, then you sand it down, and looks like a topographical map, with the colors of the glazes revealed, you see every peak and valley.”

The alchemy and chemistry of glaze are sometimes revealed at unexpected points in the process. Winnie tells a story about a surprise encounter with plastic food wrap. “I had been wrapping my bud vases in Saran Wrap to keep them moist, but then I’d unwrap it and we wound up with this spiderweb kind of effect, and you get all these wonderful patterns. It works pretty well. Or, you could spray the glaze onto the Saran Wrap with your spray gun and then wrap it, like a transfer or a decal.”

When asked about where she draws inspiration for new glazes Winnie says, “I hang out in nature a lot, and I look really closely.” She also emphasized using tools in a different way than you normally do. “Try using the corner of the sponge, make streaks, try the edge of the sponge – how is that different? Even the oil from your hands can have an effect.”

So what’s the one piece of advice she has for people who are novice ceramicists? Winnie doesn’t hesitate. “My suggestion to potters is: get a scale!” she says with emphasis. “Weigh things, and mark on the bottom of the piece the underneath weight and the top weight.” She continues. “A scale is amazing. Edith always wanted the glazes to be put on fairly thin. She wanted the flecks of manganese to show through the glaze. She was all about having the glaze be a part of the conversation. She would always have scales to make sure people put on the right amount of weight. The other thing is: take notes. Take really good notes. I have it both on the piece and in a notebook, so I can repeat it because every now and then you get these amazing things.”

Winnie cradles a bud vase in her hands that is the size and texture of an ostrich egg. “You just can’t repeat it otherwise.” Even the most precise note taker and finicky glazer are still subject to the whims of the kiln when experimentally layering glazes. At the same time, clay comes from the earth and is as similarly unpredictable as nature itself. “There’s only so much you can control,” Winnie says as she shows another vase, a success story from the accidental Saran Wrap experiment.

“It surprised us all when it came out this way.” She smiles. “But in a way, it shouldn’t surprise us.”